/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.mpp.plan.statement.component;

import org.apache.iotdb.db.mpp.plan.statement.StatementNode;

import java.util.ArrayList;
import java.util.List;

import static com.google.common.base.Preconditions.checkState;

/**
 * The order of query result set
 */
public class OrderByComponent extends StatementNode {

    private final List<SortItem> sortItemList;

    private boolean orderByTime = false;
    private int timeOrderPriority = -1;

    private boolean orderByTimeseries = false;
    private int timeseriesOrderPriority = -1;

    private boolean orderByDevice = false;
    private int deviceOrderPriority = -1;

    public OrderByComponent() {
        this.sortItemList = new ArrayList<>();
    }

    public void addSortItem(SortItem sortItem) {
        this.sortItemList.add(sortItem);
        if (sortItem.getSortKey() == SortKey.TIME) {
            orderByTime = true;
            timeOrderPriority = sortItemList.size() - 1;
        } else if (sortItem.getSortKey() == SortKey.TIMESERIES) {
            orderByTimeseries = true;
            timeseriesOrderPriority = sortItemList.size() - 1;
        } else {
            orderByDevice = true;
            deviceOrderPriority = sortItemList.size() - 1;
        }
    }

    public List<SortItem> getSortItemList() {
        return sortItemList;
    }

    public boolean isOrderByTime() {
        return orderByTime;
    }

    public Ordering getTimeOrder() {
        checkState(timeOrderPriority != -1, "The time order is not specified.");
        return sortItemList.get(timeOrderPriority).getOrdering();
    }

    public boolean isOrderByTimeseries() {
        return orderByTimeseries;
    }

    public Ordering getTimeseriesOrder() {
        checkState(timeOrderPriority != -1, "The timeseries order is not specified.");
        return sortItemList.get(timeseriesOrderPriority).getOrdering();
    }

    public boolean isOrderByDevice() {
        return orderByDevice;
    }

    public Ordering getDeviceOrder() {
        checkState(deviceOrderPriority != -1, "The device order is not specified.");
        return sortItemList.get(deviceOrderPriority).getOrdering();
    }

    public String toSQLString() {
        StringBuilder sqlBuilder = new StringBuilder();
        sqlBuilder.append("ORDER BY ");
        for (int i = 0; i < sortItemList.size(); i++) {
            sqlBuilder.append(sortItemList.get(i).toSQLString());
            if (i < sortItemList.size() - 1) {
                sqlBuilder.append(", ");
            }
        }
        return sqlBuilder.toString();
    }
}
